1. Field of the Invention
This invention relates to the use of special aroylcarboxylic acids as corrosion inhibitors in aqueous systems.
2. Statement of the Related Art
Corrosion prevention in aqueous systems is a major problem in industrial processes involving susceptible metals, such as copper, zinc or aluminium. Previously, the use of corrosion inhibitors, for example in cleaning preparations, cooling lubricants, hydraulic fluids or cooling waters, has often resulted in a number of practical problems. Foam suppression, solubility, and stability in hard water, are all important to the usefulness of corrosion inhibitors. In addition, the toxicity and degradability of corrosion inhibitors and also their shelf life are crucial factors.
Long chain aliphatic sulfonamidocarboxylic acids and arylsulfonamidocarboxylic acids have recently been proposed as corrosion inhibitors. However, they are only effective against corrosion when used in high concentrations and, in many cases, do not satisfy the performance standards mentioned above.